A filter bank multicarrier (FBMC) technology is referred to as one of candidate technologies of next generation mobile communication. Compared with a current commonly used multicarrier technology, such as a cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) technology, the FBMC technology has advantages such as a desirable outband suppression effect, high frequency spectrum utilization, and flexible use of a frequency spectrum. Multi-input multi-output (MIMO) is a technology in which multiple transmit antennas or receive antennas are used to increase a system throughput and a transmission distance, and is a mandatory technology in a current wireless communications system. In the wireless communications system, to resist impact of a radio channel on transmitted data, a receive end needs to perform channel estimation, for example, perform channel estimation in an OFDM system by using an orthogonal pilot. However, the FBMC system has inherent interference, and consequently, a sent pilot symbol is polluted at the receive end. Therefore, both design of a pilot sending algorithm and a channel estimation algorithm directly affect final channel estimation performance.
There are mainly two existing MIMO-FBMC pilot sending methods: an interference approximation method (IAM) and an auxiliary pilot method (APM). However, the IAM method has disadvantages of high pilot overheads and low spectral efficiency. Compared with the IAM method, the APM method has low pilot overheads, but an auxiliary pilot causes a power increase, and especially in an MIMO case, the power increase is severer.